View Code of Problem 92

#include<stdio.h>
#include<math.h>
int Isprime(int n)
{
	int prime,i;
	for( i=2;i<=(int)sqrt((double)n);i++)
	{
		if(n%i==0)
		{
			break;
		}
	}
	if(i>(int)sqrt((double)n))
	{
		prime=1;
	}
	else
	{
		prime=0;
	}
	return prime;
}
int BackNumber(int n)
{
	int t=1,x=n,z=n,d,sum=0;
	while(x>0)
	{
		t*=10;
		x/=10;
	}
	t/=10;
	while(t>0)
	{
		d=n%10;
		sum+=d*t;
		n=n/10;
		t=t/10;
	}
	if(sum==z)
	{
		return 1;
	}
	else
	{
		return 0;
	}
}
int main()
{
	int a,b,j=0;
	int c[1000];
	scanf("%d %d",&a,&b);
	for(int i=a;i<=b;i++)
	{
		if(BackNumber(i)&&Isprime(i))
		{
			c[j]=i;
			j++;
		}
	}
	int g=1;
	for(int k=0;k<j;k++)
	{
		printf("%6d",c[k]);
		if(g%5==0)
		{
			printf("\n");
		}
		g++;
	}
	return 0;
}

Double click to view unformatted code.


Back to problem 92